JPH01179126A - Display device - Google Patents

Abstract

PURPOSE:To eliminate a fluctuation of an image, to simplify the structure, to reduce the cost, and also, to cool a polarizing plate, etc., as well by providing a cooling means on the lower part of a liquid crystal light valve. CONSTITUTION:In a display device for leading an emitted light from a light source, to an optical waveguide 2, and forming an image by a liquid crystal light valve 3B (3R, 3G) and a prism, a cooling means is provided on the lower part of the light valve 3B. When a cooling fan 7 is used as the cooling means, cool air flows smoothly to the upper part, and polarizing plates 11B, 12B and the optical waveguide 2 in the periphery of the valve are also cooled simultaneously. Therefore, since there is no cooling part in an optical path, there is no influence exerted on an image due to a fluctuation of a liquid, the structure is simplified and miniaturized and the cost can be reduced, and also, the polarizing plate, etc. can also be cooled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a projection type display device that enlarges and projects an image formed by a liquid crystal light valve using a projection lens.

[Conventional technology]

Conventionally, as described in Utility Model Publication No. 62-33027, as shown in FIGS. 4 and 5, a cooling layer is provided on the outer surface of the liquid crystal display 20 and provided integrally with the liquid crystal display 20. 21, a mesh member 23 arranged in the cooling layer 21 and provided in a grid pattern corresponding to the gaps between the image dots of the liquid crystal display 20, and an end portion of the mesh member 23. Radiator 24 for heat dissipation to which is connected
A liquid-cooled display device using a liquid crystal light valve consisting of

[Problem that the invention seeks to solve]

However, since conventional display devices include a cooling section in the optical path, fluctuations in the liquid in the cooling section directly affect the image. Further, since the heat retained in the liquid in the cooling section is air-cooled by a heat dissipation radiator, which results in film cooling, the structure of the liquid crystal light valve becomes complicated and large, and the cost also increases. Furthermore, the conventional technology has the problem that only the liquid crystal light valve can be cooled, and it is difficult to cool the polarizing plate, which is essential for image display.

Therefore, the present invention aims to solve these problems.
The purpose of this is to simplify the structure of the liquid crystal light valve and reduce its cost, and to provide a cooling method that has sufficient ability to cool not only the liquid crystal light valve but also the polarizing plate without adversely affecting images. An object of the present invention is to provide a display device having the following features.

[Means for solving problems]

In order to solve the above problems, the display device of the present invention guides emitted light from a light source through an optical waveguide, forms an image using a liquid crystal light valve, and enlarges and projects the image using a projection lens. It is characterized by a cooling means provided at the bottom of the light bulb.

[For production]

In the display device having the above configuration, when a cooling fan is used as a cooling means to blow air from the bottom, the second
In the figure, the air from the cooling fan 7 flows smoothly over the surface of the liquid crystal light valve 3B as shown by the thick line in the figure, and as an air cooling system, it not only directly cools the liquid crystal light valve 3B, but also
The surrounding polarizing plates 11B, 12B, optical waveguide 2, etc. are also cooled at the same time and blow through to the outside of the national polity 14.
It is possible to suppress the temperature rise of the internal air and also suppress the temperature rise of the liquid crystal light valve 3B due to heat conduction.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. FIG. 1 is a plan view showing a basic configuration diagram representing one embodiment of the present invention. The light emitted from the light source 1 is separated into three primary colors of red, green, and blue and guided within the optical waveguide 2, and is modulated by the liquid crystal light valves 3R13G and 3B corresponding to each color. LCD light bulb 3R, 3G, 3
B is a guide plate 4R14 for fixing and adjusting, respectively.
G, 4B, and has two polarizing plates each on the front and rear of the optical path for image display. The light transmitted through the liquid crystal light valves 3R, 3G, and 3B undergoes light synthesis by the prism 5, and is enlarged and projected onto the screen in front by the projection lens 6.

On the other hand, since these display devices require high luminous flux as their basic performance, they are inevitably equipped with liquid crystal light valves 3R, 3G,
3B and the temperature rise on the polarizing plate accompanying them becomes significant. Therefore, in this embodiment, the cooling fan 7 is used as a formula to spray the lower parts of the three liquid crystal light valves 3R, 3G, 3B and the six polarizing plates attached thereto.
Air-cools the liquid crystal light valve and surrounding parts.

FIG. 2 is a cross-sectional view of the embodiment shown in FIG. 1, viewed from the projection lens 6 side, and is enlarged for blue. The liquid crystal light valve 3B is fixed to the guide plate 4B by a liquid crystal light valve fixing plate 8B, and is held relative to the prism 5 by fixing the guide plate 4B to a prism fixing plate 9.10 that fixes the prism 5 vertically. Ru. The liquid crystal light valve 3B has polarizing plates 11B on the front and back on its optical path.
and 12B to enable image display. The prism 5 and the liquid crystal light valve 3B are held at an appropriate distance from the national polity 14 by fixing the prism fixing plate 10 to the national polity 14 via a spacer 13, and a cooling fan 7 is provided in the space created thereby. At this time, by providing suction holes and exhaust holes in the national body 14 and providing ventilation holes in the prism fixing plate 9 and lO, a wind as shown by the thick line in FIG. 2 is generated inside the display device, and the liquid crystal light valve 3B and Polarizing plates 11B and 12B are air-cooled. After a while after the power is turned on, the temperature of the air inside the display device increases due to heat conduction from the light source 1, optical waveguide 2, etc., but the present invention allows cooling by smooth air flow. The temperature rise can be suppressed as much as possible, and the liquid crystal light valve 3B and polarizing plates 11B and 12
The temperature rise due to the rise in the internal air temperature of B can also be suppressed to the minimum. At this time, if the air guide plate 15 shown in FIG. 2 is provided on the upper surface of the cooling fan 7, the efficiency of the cooling capacity will increase, and the effectiveness of the cooling fan will be further improved.

As described above, according to the present invention, the liquid crystal light valve 3R,
Since there is no need to provide heat dissipation capability to the liquid crystal light valves 3G and 3B themselves, the shapes of the liquid crystal light valves 3R, 3G and 3B are, for example, as shown in FIG.
It can be simplified to consist of a frame substrate 18 and a card edge 19.

〔Effect of the invention〕

As explained above, by providing a cooling means at the bottom of the liquid crystal light valve, the present invention enables air cooling by natural wind flow, making the structure of the liquid crystal light valve extremely simple and compact, resulting in low cost. At the same time, it is possible to realize a display device that can sufficiently cool not only the liquid crystal light valve but also the polarizing plate without adversely affecting the image.

[Brief explanation of the drawing]

FIG. 1 is a basic configuration diagram showing an embodiment of the present invention, FIG. 2 is a detailed cross-sectional view of the blue color in the embodiment of FIG. 1, and FIG. 3 is a diagram of a liquid crystal light valve in an embodiment of the present invention. FIG. 4 is a front view of a liquid crystal light valve in a conventional display device, and FIG. 5 is a schematic front view of a liquid crystal light valve in a conventional display device.
It is an A sectional view. 1... Light source 2... Optical waveguide 3R, 3G, 3B... Liquid crystal light valve 4R, 4G,
4B... Guide plate 5... Prism 6... Projection lens 7... Cooling fan 8B... Liquid crystal light valve fixing plate 9/10... Prism fixing plate 11B/12B... Polarizing plate 13 ... Spacer 14 ... National polity 15 ... Wind guide plate 16 ... Liquid crystal display 17 ... Driver 18 ... Frame board 19 ... Card Edge and above Applicant Seiko Epson Corporation Figure 1 Figure 2 Figure 4

Claims (1)

[Claims] A display device that guides emitted light from a light source through an optical waveguide, forms an image using a liquid crystal light valve, and enlarges and projects the image using a projection lens, characterized in that a cooling means is provided below the liquid crystal light valve. display device.